The Philadelphia Phillies have signed right-hander David Robertson to a one-year contract, bolstering their bullpen in a bid to outlast the New York Mets and win a second straight NL East title. Phillies president of baseball operations Dave Dombrowski made the move Monday, optioning the 40-year-old reliever to Triple-A Lehigh Valley. Robertson was a key pitcher for the New York Yankees when they won the 2009 World Series and was an All-Star two years later with the franchise.